1. Field of the Invention
The present invention generally relates to using an external energy source to deposit an electrical charge to an electrical storage cell. More particularly, the invention concerns an apparatus and method for delivering energy to an electrical storage cell--such as an automotive battery--that has dissipated sufficient energy to no longer be able to supply adequate energy for the application into which the storage cell is installed.
2. Description of the Related Art
In an electric storage cell, or battery, chemical energy is converted into electrical energy. Strictly speaking, the word "battery" applies to an assembly of cells, but the word has come to mean single unit or cells. A battery utilizes the potential difference which exists between elements within the cell. When two different elements are immersed in electrolyte, an electro-motive force ("emf") exists tending to send current within the cell from the negative pole, which is more highly electro-positive, to the positive pole. The poles, or electrodes of a battery, form the junction to which an external circuit can be attached to the battery. If the external circuit is closed, current flows from the battery at the positive electrode, or anode, through the external circuit, and enters the battery at the negative electrode, or cathode.
There are two types of batteries: a primary battery and a secondary battery. In a primary battery, the chemical-reacting parts require renewal after use. In a secondary battery, the electro chemical processes are reversible to a high degree, and the chemically reacting parts are restored after partial or complete discharge by reversing the direction of current through the battery. An automotive battery is an example of a secondary battery.
The emf of a battery is the total potential difference between the electrodes on open circuit. When current flows, the potential difference across the terminal drops because of a resistance drop within the cell and because of polarization. Polarization occurs when current flows in the battery and a substance, such as hydrogen, is deposited on the cathode due to the chemical reaction taking place within the batteries. The deposits cause two effects, both of which are well-known in the art, which reduce the terminal voltage of the battery.